A Plasmon-Mediated Cold-Cathode

Light-driven electron emission plays an important role in modern electronic and optoelectronic devices. However, such a process usually requires a light field either with a high intensity, or with a high frequency, which is not in favor of its applications. To solve these issues, we propose and realize a plasmon-mediated cold-cathode (PMCC), which combines plasmonic nanostructures with nano-electron-emitters of low work function. In a PMCC, hot-electrons generated by plasmon resonances upon light excitation will enter into adjacent emitter, and subsequently emit into vacuum. PMCCs greatly benefit from strong energy coupling of plasmonic effect, and work based on a plasmon-mediated electron emission process. Electron emission of high efficiency can be obtained with light field of moderate intensities and visible wavelengths. This electron emission is of interest for applications including cold-cathode electron sources, advanced photocathodes, and micro- and nano-electronic devices relying on free electrons. The above findings will be presented with a review of progresses in the study of such a light-driven electron emission.